Production of carbon dioxide snow



Jan. 10, 1950 V w. H. FREYGANG 2,493,759

PRODUCTION OF CARBON DIOXIDE SNOW Filed Nov'. 28, 1944 28 22 5 2 J/ 1 1 02, INVENTOR MU E RHFRHGANG ATTORNEY Patented Jan. '10, 1950 PRODUCTION OF CARBON DIOXIDE SNOW Walter H. FreygangfEssex Fella, N. J., assignor to Kidde Manufacturing 00., Inc., a corporation of Delaware Application November as, 1944', Serial No. 565,543

(Cl. oz-izi) Claims.

' l The present invention relates to methods of, and devices for, forming carbon dioxide snow,

and particularlyto forming the snow for therapeutic and other applications. v

The invention aims to provide a small light weight manipulatable snow producing device for the more efiective reception and use of containers or cartridges of liquid carbon dioxide which ordinarily are generally available and may be main-' tained in stock without deterioration, and from which the snow may quickly and easily be pro-' duced as needed, without dependence upon solid carbon dioxide.

An object of the invention is to form the snow more efiectively and in larger proportion to the quantity of carbon dioxide from which it is produced than heretofore.

Another object is to provide novel means for cooling carbon dioxide during the production of snow therefrom.

Another object is to improve the control of gas pressure incident to the production of carbon dioxide snow.

Another object is to prevent the ingress of foreign substances to the snow during the formation thereof, and to the apparatus for producing it.

Another object is to form carbon dioxide snow in a manner to facilitate temporary storage thereof with a minimum loss due to the subliming of the snow.

Another object is to provide an applicator which is novel in itself and in cooperation with the other elements of the invention for more eil'ectively forming and applying the show.-

A further object is to provide carbon dioxide snow producing means of the above indicated character that shall be simple and durable in construction, economical to manufacture, and effective in its operation.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawing, forming a part of the specification, wherein:

Figure 1 is an enlarged side view, generally in longitudinal central section, with parts in eleva-,

tion. of a device constructed in accordance with the invention.

Figure 2 is a view taken substantially along the line 2--2 of Figure 1. Y

- Figure'3 is a bottom plan view of the device.

Figure 4 is a detail bottom plan View of an v 2 applicator seat shown near the bottom of Figure 1.

Figure 5 is a detail plan view of a filtering unit shown near the top of Figure 1.

Figure 6 is a view illustrating a device for applying carbon dioxide snow.

Referring to Figure 1, the device therein shown comprises in general, a base In, a casing l2, an

inlet structure II, a snow receiver and applicator receptacle l5, and a support or enclosure shell It for a cartridge l8 oi? carbon dioxide.

The base Referring to Figures 1 and 3, the base l0 comprises a member 20 constructed, in this instance, of opaque black plastic heat insulating material, such as Lucite, but which may be clear or otherwise colored and constituted of other material. The base member 20 is of substantially cup shape, the side wall 22 of which has internal screw threads, and the bottom wall 23 of which is provided with an inner side annular channel 24 having bottom vents 26. A spring 28 is seated on thebottom of the channel near the outer periphery thereof, and a portion 30 defined by the channel centers a spring 32 seated in the channel.

The base member 20 is further provided with uniformly peripherally spaced longitudinally extending outer side ribs 34, in this instance of half round section, facilitating hand grip turning of the base relative to the casing l2. The ribs 34 are disposed in lower end-to-end relation to shortsimilar ribs 36 extending radially inwardly on the outer bottom surface of the base member 20 for resting on a support 38 representing a table top or other substantially horizontal plane seat.

The ribs 36 thus provide spaces 40 between the bottom wall 23 and the support 38, and between tended. The arrangement prevents tilting or up-- setting of'the device or causing it to walk" oi! the support which may be narrow, or adjacent to an edge of which the device may conveniently be placed without danger of injury to the device or surroundings from such movements.

A seat retainer 42, ofclear Lucite," but which may be of other material, is disposed in the base member 20 and provided with a lower portion 44 threaded to the base. Anupper'portion 46 of the retainer 42, of smaller diameter than the portion 44 is provided with a flange or shouldered structure 48 having a plane lower face normal to the axis of the device and an upper face sloping inwardly and downwardly.

' Referring to Figures 1 and 4, an applicator seat ill, disposed in the retainer 42, is generally of disc-like form having outer peripheral flange portions 52, an upper concave conical seat surface 54, a central valve aperture 56, and bottom l and having vent slots 82.

projections 88 forming guides for a valve member The seat 88 is maintained in the position shown, against the bottom of the applicator I5, by the spring 28 and is prevented from ejection from the retainer 42 by the flange 48. The latter is spaced sufllciently above the flange 52 to ensure proper seating of the applicator I5 shown, which is one of several similar applicators of the same length" and diil'erent diameters for seating and centering by the conical'seat surface 54.. Consequently, by reason of such different diameters, the flange I2 will assume different positions relative to the flange 48, but never engage it except.

in the absence of the applicator. The arrangethereto into a recess 88 in the end wall 10. The tube '84 has a substantially small diameter and ment also compensates for minor variations which may occur in the lengths of the applicators.

The valve member 80, of material, such as clear on the seat 50, and has av lower projection fltte into the spring 82. I

The casing The casing I2, which may be of any of various materials, but, which, in this instance, is of clear plastic heat insulating material, such as Lucite, is of normally inverted substantially cup shape having relatively thick side and closed end walls 08 and II, respectively, a lower end portion I2 of reduced diameter threaded to the base I0 in a recess formed between the upper portion 46 of the retainer 42 and the upper side wall portion of the base member 28.

Referring to Figures 1 and 2, the closed upper end of wall III of the casing I2 has rounded outer surface contour between this end and the side wall 88, and a downwardly convex axially centered conical inner seat surface 18 having radial grooves 88, which surface and groove portions are also parts of the inlet structure I4. By this construction, any of the applicators I5'may be seated Y on, and centered by, the surface 18 as pressed thereagainst by the lower seat 80 and the spring 28. The grooves 80 provide upper end relief for gas pressure in the applicator I5, irrespective of the diameter of the latter. The seats 54 and I8 are both conical and, asshown, are such that the seat I8 extends into one end portion of the applicator, the other end of which extends into the seat 84, although this relation may be reversed,

and the conical seats both constructed concave or convex and have parabolic or other'shape for the same purpose.

The inlet structure The inlet structure I4, in addition to the surface I8 and the grooves 88, comprises a cup-like member 82 partially molded in the end wall I0, with its embedded bottom end 84 provided with an aperture 88. The cup 82, which in this instance is of metal, such as brass, but which may be of other material and shape, is exteriorily screw threaded and has a mouth end length 80 wall of the tube is substantially thin to provide v for high heat conduction. The tube extends axially through the center of the seat surface 18, see Figure 2, and along the center of the applicator tube It therein to a position close to the :gttom end of the tube I I adjacent to the seat A disc-like filtering screen I88, as better seen in Figures 1 and 5,'is disposed in flat-layer relation to the holder 82 thereover, and comprises a central area of fine mesh metal screening I02,

such as copper, embedded or molded in a margin I04 of plastic or composition material, such as Lucite, Bakelite or the like.

, A holder I08, for a metal tubular piercing pin I08, is of centrally apertured relatively thick metal disc character fltted in the cup 82 over the screen I00, into the aperture of which the pin I08 is press fitted against a shoulder IIO around the disc aperture with the pin protruding upwardly from the disc to a sharp pointed end.

, A flat washer-like metal screw II2 cooperating with. the inner threads of the length 80 of the cup 82 therein clamps or presses all of the parts 82, I00 and I08 against the bottom wall or end 84 of the cup, and has a frusto-conicalrecess in which is'disposed a washer II4 of yieldable material, such as rubber, around the pin I88.

The applicator The applicator IS, in this instance, is an open tube, or a tube in which the bore extends enceptacle in which the snow is formed.

protruding from the end wall I0 and provided with interior screw threads.

A holder 82, fora cooling or heat exchange tube 84, is of substantially disc-shape closely conforming to the inner side and bottom surfaces of the cup 82 and is provided with an extension 88 providing press flt length grip along a substantial area of the tube 84 and extending through the aperture 88 of the cup 82 in close fitting relation The applicator I 5, is constructed of heat incilitate handling, to enable the operator to at all times have a clear view of the snow, and to avoid easy breakage. The applicator is provided with a series of apertures 01' perforations I20 which are uniformly distributed through the side wall of the tube, beginning at a position somewhat removed from the lower end of the-applicator and from the lower end of the heat exchange tube 84, and extending upwardly on the tube to a position somewhat below the top end thereof. The apertures I20 are large enough to provide for the relief of gas pressure in the applicator, and small enough to prevent snow particles from being ejected therethrough by a plunger or piston I2I, see Figure 6, operating in the applicator tube, as in a piston cylinder, from the end II8, for compacting and pressing the snow toward the applying end II8. Instead of providing the apertures I20 to renderthe applicator gas permeable, the applicator may be formed of porous material, such as unglazed refractive or ceramic material.

The cartridge support The support I6 for the cartridge I8 is an elonated metal shell somewhat on the order of a tire-valve cap, but having a vent I 22 and lower length outer longitudinal ribs I24 to facilitate under pressure. Cartridges of the type illustrated.

herein may ordinarily be readily obtained, and may be conveniently stored. Preferably, the cartridges are stored in a cool place, such as a refrigerator, to obtain the optimum yield of snow for a given weight of liquid carbon dioxide.

The cartridge has a puncturable metal seal I26 held in the head end I28 of the neck I30 of the cartridge, as by crimping the edges of the head end I28 inwardly against the seal I26, which, in turn, is pressed against a compressible gasket. The inner length of the shell I is such, relative to the length of the cartridge it, that the shell and the cartridge may be mounted on the casing partially screwed to the cup 82 in readiness for puncture of the seal I! by the piercing pin Ill when the shell is further advanced into the cup 82, or the shell, with the cartridge therein, may be fully turned onto the cup in one continuous operation for sealing the shell to the casing and releasing the carbon dioxide.

Operation tube or needle II, with the casing I! held in inverted upright position or sufficiently so to prevent the applicator from falling out of the casing, the end 6 will tend to center seat itself on the conical seat 18, with the inner tip of the latter protruding slightly into the applicator and lateral movement of the latter limited by the heat extractor tube 94; The applicator being of exceedthe tube while at or slightly lower than atmospheric temperature, is substantially cooled to increase its snow forming capacity when expanded at the outlet of the tube.

The gaseous carbon dioxide then passes through the apertures l2ll in the applicator and the grooves ll of the upper applicator seat 18 into the chamber of the casing l2, wherein it is further expanded to provide additional cooling eflects ambient to the applicator, and then escapes to the atmosphere by way of the vent slots 62 in the applicator seat 50 and the venting apertures 26 in the base 20.

As snow is formed at the bottom of the applicator, this snow is progressively crowded upwardly in the applicator by snow formed thereafter, whereby, first the lower end of the tube 94 and then the intermediate portion thereof are surrounded with snow which effects cooling of the liquid carbon dioxide being delivered by the tube. In this manner the thermodynamic properties of the liquid carbon dioxide during its expansion are fully utilized, whereby an opingly light weight, and the tube 94, although of fine diameter and bore, being relatively strong, the tube SI is capable of thus limiting slight lateral movement of the applicator without danger of injury to either element, and holding the applicator for the mounting of the base 20.

When the base is advanced onto the lower end of the casing l2, the lower conical applicator .seat 5. yieldingly engages the end 8, and if the applicator I5 is not centered when engaged by the seat 5!, itwill be centered by this seat, and also relative to the seat It, by the uniform perimetral pressure of the spring seat 50 in the applicator.

With the device thus in readiness, the shell ii, containing the cartridge i8, is next advanced onto the cup l2, during which the seal I26 is punctured. Upon this action, the carbon dioxide is released, under its pressure, to flow to the tube 94 by way of the piercing pin I08, and the screen I00 which retains any foreign matter which might block the bore of the tube 94. The tube 94 by having a relatively small bore acts as a snow forming orifice at its outlet end for converting a substantial amount of expanded liquid carbon dioxide to carbon dioxide snow which is deposited at the bottom of the applicator.

The remainder of the liquid carbon dioxide is expanded to gaseous carbon dioxide having a relatively low temperature which flows upwardly in heat exchange relation with the tube 54 to effect cooling of the liquid carbon dioxide being delivered to the outlet end of the tube. In this manner the liquid carbon dioxide, which enters timum yield of snow is obtained. 7

In the event that the pressure in the applicator due to the rapid expansion of the carbon dioxide becomes excessive or greater than a predetermined value, the valve member in is moved from its seat in opposition to its spring to momentarily vent this pressure and to restore the desired pressure conditions in the applicator. The valve member 60 by operating in this manner functions as a safety valve. The gaseous carbon dioxide vented to the atmosphere by reason of the operation of the valve member GI and the normal flow of gas through the vent slots i2 passes through the vents 26 of the base and the spaces at the bottom of the base .without upsetting or causing walking of the device.

After a charge of snow has been formed in the applicator, the applicator may be permitted to remain in the casing l2 whereby the snow, due

to its cool surroundings, sublimes at a low rate. This enables a physician to make the snow when preparing for an operation and any unforeseen delay in commencing the operation will not cause any substantial decrease in the amount of snow available. The gas formed due to the subliming of the snow in the applicator escapes through the slots 62 in the lower seat 50, the vents 26 in the base and the spaces 40 at the bottom of the base and harmlessly flows to the atmosphere.

When the applicator is removed from the casing it, the piston or plunger i2l is inserted into the end Iii and the snow is advanced toward the end 8 for application, as indicated in Figure 6.

From the foregoing description, it is apparent that a method and a device of the character described have been provided which very materially advance the art to which they relate, and that the device is a simple, economical, ornate, rugged, durable, dependable and effective unit of many other merits, constituting it a desirable acquisition to professional equipment and a new help to those who may require its benefits.

As various changes maybe made in the form, construction and arrangement of the parts herein, without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as,illustrative and not in any limiting sense.

It is also to be understood that the following claims are intended to cover all the generic and and all statements oi the scope of the invention I which, as a matter of language, might be said to fall therebetwecn.

I claim:

l. A device for producing snow from carbon dioxide, comprising meansforming a chamber including an inlet and having oppositely disposed portions for positioning snow receiving means in communication with said inlet, and means for supporting the snow receiving means including a cone-like seat for at least one of said portions.

2. A device for producing snow from carbon dioxide, comprising means forming a chamber adapted for the reception of snow receiving means, and means for positioning the receiving means including a yieldable support having a valveopening, and means including a valve for. controlling the passage of fluid through said opening. 1

3. A device for producing carbon dioxide snow, comprising a casing having an open end, an iniet and a seat around said inlet for supporting one end of an applicator tube, in communication with said inlet, a source of carbon dioxide adapted to be placed in communication with said inlet, a detachable closure for the open end of said casing having a vent, means within said said valve member to normally said valve 7 opening relative to said vent means.

6. A device for producing snow from carbon dioxide. comprising means forming a chamber, a tube open at both ends disposed in said chamber, said chamber having means for substantially closing the open ends of said tube when disposed therein; and means extending into said tube through one 01' its ends and-termi'nating'adja-v cent its other end for introducing carbon dioxide into said tube.

7. A device for producing snow from carbon dioxide, comprising means forming a chamber, a tube removably supported in said chamber, and inlet means extending through said tube for a substantial portion of its length for introducing carbon dioxide into said tube adapted to form a snow therein; said tube maintaining the snow casing adjacent to said closure having a yieldable seat for supporting the other end or the applicator tube and having a valve opening, and a valve member controlling seat valve opening and normallyyieldably closing said valve opening.

4'. A device for producing carbon dioxide snow, comprising a casing having an open end, an inlet and a supporting surface around said inlet for one end of an open applicator tube in communication with said inlet, an inlet tube supported by said casing and extendingfrom said inlet to position in the casing to be surrounded by the applicator tube, a source of carbon idioxide adapted to beplaced in communication with said inlet, a closure base for the open end of said casing having a vent, means within said casing adjacent to the base providing a yieldable support for the other end of the applicator tube and having a valve opening, and a valve member controlling seat valve opening normally yieldably closing said valve opening;

5. A unit for producing carbon dioxide snow, comprising a cup-like casing having an open end and an end wall provided with an axially centered radially grooved convex, conical inner surface constituting a centering seat for one end 'of an open applicator tube, said end wall being provided with an inlet, an inlet tube having a relatively small bore, said inlet tube having one'end in communication with said inlet and extending substantially to said open end to be surrounded by the applicator, a source of carbon dioxide mounted on said casing and adapted to be placed in communication with said inlet, a filtering screen intermediate said source and said inlet, a base cup having bottom vent means and exterior side and bottom ribs and detachably threaded 5 to said open end of said casing, a sleeve-like seat retainer-threaded to said base cup therein and having an inner flange, a movable seat in said sleeve having a valve opening and a concave conical seating surface around said opening for the other end of the applicator tube, a valve member for said valve opening, and separate springs backed by said bottom, and respectively, biasing said seat toward the position to be occupied by the applicator tube and said flange and biasing in heat exchange relation with said inlet means to remove heat from the carbon dioxide passing through said inlet means, whereby the yield of snow is increased.

-8. A device for producing snow from carbon dioxide, comprising means forming a chamber, a tube open at both ends disposed in said chamber, inlet means extending into said tube through one of its ends for introducing carbon dioxide.

into said tube, means for positioning said one end around said inlet means and for substantially closing the same, and meansfor closing the said other end and yieldably biasing said tube toward said positioning means.

9. A device for producing snow from carbon dioxide, comprising means forming a chamber adapted for the reception of snow receiving means. said chamber having an inlet and an outlet, a closure structure for said outlet having a bore therein and a substantially closed end provided with venting means, means for positioning the receiving means including a spring biased seat member in said bore having a valve opening therein; and valve means for controlling the passage of fluid through said opening.

10. A unit for producing carbon dioxide snow, comprising a casin a removable snow receiving member in said casing. said casing providing an abutment for one end of said member, a fixed.

inlet tube supported by said casing and extending into said member'to a position adjacent the other end thereof, a source of carbon dioxide adapted to be placed in communication with said inlet tube for introducing carbon dioxide into said member to form snow therein, and means for removably supporting said member in said casing in heat exchange relation to said inlet tube.

WALTER. H. FREYGANG.

REFERENCES CITED The following references are of record in the file of this patent: p I

UNITED STATES PATENTS 

